Traditional bedsheet products made from woven fabric constructions have several disadvantages. For instance, the bottom sheets oftentimes do not hold their fit position properly, and all of the bottom sheets, top sheets, and pillow cases have potentially harsh hand if optimum laundering procedures are not followed. Also, woven bedsheets prepared from cotton wrinkle easily unless provided with permanent press resin finish or unless constructed with a fairly high percentage of synthetic fiber yarn to provide a smooth appearance after washing. However the durable press resin finished sheets, and sheets made from conventional synthetic fiber blends, often have a harsh hand.
In order to overcome the problems associated with woven fabric constructions of bedsheets and pillow cases, sheets have been prepared--particularly fitted contour (bottom) sheets--from 100 percent cotton in a jersey knit construction, such as shown in U.S. Pat. No. 3,789,441. While such sheets solve the harsh hand problem, at least during early stages of their life, while having a no-iron construction, such sheets have problems of their own. For instance the 100 percent cotton fabric is weak, tears easily, absorbs and maintains moisture too readily, and often becomes harsh over time.
According to the present invention, a sheeting product is provided which overcomes the problems inherent in the prior art as discussed above. The invention relates to the construction of top sheets, bottom (fitted contour) sheets, and pillow cases which have numerous advantages compared to one or all of the prior art products discussed above. The invention relates to sheeting products, and a method of producing sheeting products, from a sheath and core yarn. The sheath fibers completely cover the core fibers, comprising more than 50 percent of the yarn, and preferably about 68-83 percent of the yarn. The sheath fibers are short staple fibers, such as cotton or cellulosic fibers having smoothness of hand properties comparable to cotton (when constructed into a fabric). The core fibers have properties distinctly different from the sheath fibers. Preferably the core fibers are long staple synthetic fibers, which have enhanced strength compared to the sheath fibers. The preferred core fiber is polyester, or synthetic polymer fibers that are comparable to polyester as far as strength, softness, and wicking properties are concerned.
The sheath and core yarn according to the present invention preferably is produced as set forth in co-pending application Ser. No. 824,788, filed Jan. 31, 1986 entitled "Roving Blending for Making Sheath/Core Spun Yarn" now U.S. Pat. No. 4,711,079 granted Dec. 8, 1987, the disclosure of which is hereby incorporated by reference herein.
In the practice of the present invention, the sheath/core yarn is circular knit into a fabric, preferably into a jersey knit configuration on a conventional circular knitting machine. Typical fabric weight is about four ounces per square yard utilizing a yarn count of thirty two singles (32/1). The knit fabric is also preferably finished to give a relaxed shrinkage of about five percent in both the length and the width dimensions. The fabric is then formed into a top bedsheet, bottom bedsheet, or pillow case by conventional techniques.
The sheeting products according to the present invention have the following advantages compared to one or all prior art constructions discussed above: They have longer wear life than 100 percent cotton. They remain softer after repeated washing and tumble drying over a longer period of time. They absorb moisture more quickly and dry more quickly because the moisture is wicked through the polyester core from moist to dry areas, and during drying will return moisture from the wet core to the drying cotton sheath areas. Since a staple fiber core is provided, it is softer than comparable sheath and core yarns prepared with continuous filament synthetic cores. The product is stronger than 100 percent cotton knit sheeting, having better abrasion resistance, greater bursting strength, and greater tearing resistance. The sheeting according to the invention also has superior stretch and recovery properties compared with 100 percent cotton, is more wrinkle resistant with improved no-iron characteristics, and is more comfortable because of smoother surface characteristics and moisture wicking characteristics.
It is the primary object of the present invention to provide top sheets, bottom sheets, and pillow cases (and a method of producing the same) having good hand and surface characteristics, good strength, and numerous other advantages. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.